Laryngeal Nerve Palsy

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Laryngeal nerve palsy

Description

Laryngeal nerve palsy is damage to the recurrent laryngeal nerve (or less commonly the vagus nerve) that results in paralysis of the larynx (voice box). Paralysis may be temporary or permanent. Damage to the recurrent laryngeal nerve is most likely to occur during surgery on the thyroid gland to treat cancer of the thyroid. Laryngeal nerve palsy is also called recurrent laryngeal nerve damage.

The vagus nerve is one of 12 cranial nerves that connect the brain to other organs in the body. It runs from the brain to the large intestine. In the neck, the vagus nerve gives off a paired branch nerve called the recurrent laryngeal nerve. The recurrent laryngeal nerves lie in grooves along either side of the trachea (windpipe) between the trachea and the thyroid gland.

The recurrent laryngeal nerve controls movement of the larynx. The larynx is located where the throat divides into the esophagus, a tube that takes food to the stomach, and the trachea (windpipe) that takes air to the lungs. The larynx contains the apparatus for voice production: the vocal cords, and the muscles and ligaments that move the vocal cords. It also controls the flow of air into the lungs. When the recurrent laryngeal nerve is damaged, the movements of the larynx are reduced. This causes voice weakness, hoarseness, or sometimes the complete loss of voice. The changes may be temporary or permanent. In rare life-threatening cases of damage, the larynx is paralyzed to the extent that air cannot enter the lungs.

Causes

Laryngeal nerve palsy is an uncommon side effect of surgery to remove the thyroid gland (thyroidectomy). It occurs in 1% to 2% of operations for total thyroidectomy to treat cancer, and less often when only part of the thyroid is removed. Damage can occur to either one or both branches of the nerve, and it can be temporary or permanent. Most people experience only transient laryngeal nerve palsy and recover their normal voice within a few weeks.

Laryngeal nerve palsy can also occur from causes unrelated to thyroid surgery. These include damage to either the vagus nerve or the laryngeal nerve, due to tumors in the neck and chest or diseases in the chest such as aortic aneurysms. Both tumors and aneurysms press on the nerve, and the pressure causes damage.

Treatments

Once the recurrent laryngeal nerve is damaged, there is no specific treatment to heal it. With time, most cases of recurrent laryngeal palsy improve on their own. In the event of severe damage, the larynx may be so paralyzed that air cannot flow past it into the lungs. When this happens, an emergency tracheotomy must be performed to save the patient's life. A tracheotomy is a surgical procedure to make an artificial opening in the trachea (wind-pipe) to allow air to bypass the larynx and enter the lungs. If paralysis of the larynx is temporary, the tracheotomy hole can be surgically closed when it is no longer needed.

Some normal variation in the location of the recurrent laryngeal nerve occurs among individuals. Occasionally the nerves are not located exactly where the surgeon expects to find them. Choosing a board certified head and neck surgeon who has had a lot of experience with thyroid operations is the best way to prevent laryngeal nerve palsy.

Alternative and complementary therapies

There are no alternative or complementary therapies to heal laryngeal nerve palsy. The passage of time alone restores speech to most people. Some alternatives for artificial speech exist for people whose loss of speech is permanent.

Resources

PERIODICALS

Harti, Dana M. and Daniel F. Brasnu. "Recurrent laryngealnerve paralysis:Current concepts and treatment." Ear, Nose and Throat Journal 79, no. 12 (December 2000): p 918.

OTHER

University of Virginia Health System. "Surgical Tutorial: Surgical Approach for a Thyroid Mass." University of Vir ginia Health System, Department of Surgery. Copyright1998-2001. 19 July 2001 <http://hsc.virginia.edu/surgery/tutorialsurgthyroid.html>.

Tish Davidson, A.M.

KEY TERMS

Aortic aneurysm

—The ballooning of a weak spot in the aorta (the major heart artery).

Thyroid gland

—A gland that produces hormones that regulate the body's metabolism. It is shaped like a flying bat with its wings outstretched and lies over the windpipe in the front of the neck.

Gale Encyclopedia of Cancer